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United States Patent | 5,034,669 |
Sako ,   et al. | July 23, 1991 |
A regenerative control circuit for controlling the regenerative energy of an electric motor drive system includes a regenerative energy dissipating resistor connected in parallel to a main smoothing capacitor through a switching element, a comparator connected to the switching element and adapted to produce an output signal to drive the switching element, a regenerative reference voltage rectifying circuit connected to a 3-phase a.c. power source, a regenerative reference voltage smoothing capacitor connected to the output of the regenerative reference voltage rectifying circuit, and a regenerative circuit including a regeneration transistor for entering a voltage difference, which is created between the main smoothing capacitor and the regenerative reference voltage smoothing capacitor by regenerative energy in certain circumstance, to the comparator. The circuit operates to control the regenerative energy, while maintaining the voltage of the main smoothing capacitor constant.
Inventors: | Sako; Akira (Aichi, JP); Tsutsumishita; Yoji (Aichi, JP) |
Assignee: | Mitsubishi Denki Kabushiki Kaisha (Tokyo, JP) |
Appl. No.: | 539494 |
Filed: | June 18, 1990 |
Oct 04, 1989[JP] | 1-257912 |
Current U.S. Class: | 318/376; 318/63 |
Intern'l Class: | H02P 003/00 |
Field of Search: | 312/363,375-378,759-763,87,88 318/379-381,362,366,367,63,86,794,817 |
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4434393 | Feb., 1984 | Kobari et al. | 318/762. |
4521724 | Jun., 1985 | Sakamoto et al. | 318/762. |
4545464 | Oct., 1985 | Nomura | 318/762. |
4620272 | Oct., 1986 | Fulton et al. | 318/762. |
4667776 | Mar., 1987 | Nomora | 318/759. |
4761600 | Aug., 1988 | D'Atre et al. | 318/759. |
4823066 | Apr., 1989 | Yoshiki et al. | 318/759. |
Foreign Patent Documents | |||
60-62823 | Apr., 1985 | JP. | |
62-25883 | Feb., 1987 | JP. |